Damp under the floor

[237SJ]

The skirting board in the corner of the living room has been a bit discoloured for a while and I felt it to see if it was damp and I decided it wasn`t. I`ve just done the hoovering and was shocked that the beading nearby disintegrated when I put the hoover on it. There`s definitely damp there and some of the block flooring looks like its starting to lift. The beading is underneath a radiator and although there is a bit of corroding on the pipe that comes out to the radiator, I don`t think it`s leaking. The other side of that wall has a washing machine and the soilpipe which comes down from the bathroom. It`s quite worrying and I don`t know where to start. Would I need a plumber? a builder? or someone else? The radiator is a drop system so there should be no pipes under the floor.

[Mosaic]

When you say 'a bit of corroding' can you be more specific? Or else, try wrapping a clean dry piece of kitchen roll round the corroded bit, then inspect it tomorrow - any wet or not will tell you if there is a leak there.
What kind of wall separates this from the washing machine and soil pipe?

Does this wall look, feel or smell wet?

I expect you'd smell a clue if the leak is coming from the soil pipe.

Ditto the washing machine - smella of laundry water etc.

My guess from what you've said is that the radiator has been oozing steadily for a few years, so hopefully giving it all a good looking at and replacing the rad will allow everything to dry out.

[Mosaic]

smella - must have been channelling Mario

[237SJ]

Thanks mosaic. You know where the radiator pipes come out of a wall and then there`s a 90 deg bend and a joint? Well both joints on that radiator have gone green but it looks like that`s because of slight dampness around the joints. The actual pipes that come out are completely dry as is the wall. I`m really hoping it`s a leak from the washing machine on the other side of the wall but there`s nothing running out along the floor tiles.

[Mosaic]

What about the radiator itself - any signs of paint coming off its base?

[237SJ]

No, it`s completely dry and clean. The system is not really that old - I installed it when moved in in 1999. I suppose there is a remote chance it could be something going on under the neighbour`s house (it`s a terrace) but it looks like whatever it is is coming upwards rather than downwards.

[Mosaic]

Well, the block floor that's lifted is banjaxed anyway, so if you can ease it out and begin some investigations. Is the skirting board behind the rad sound, or has greyish mould taken over at its base?
I think the skirting will have to come off anyway, so if you're up to it begin the happy process of prying it away from the wall. This will give you a clearer view of the supporting wall and the floor underneath.
Is this floor wooden (suspended) or solid?

If solid, seeing below is going to involve digging. You could ease up part of a suspended floor for a look.

What about the other side - have you had a good close look around the washing machine and soilpipe to see if ought is amiss?

I'm beginning to think 'house insurance'......

[EDDIE51]

Looks like a small leak on the radiator joints, they would not go green unless they were damp . As said wrap the joints in kitchen roll as you have been told and check for dampness.

[237SJ]

The floor is solid (that`s why the central heating was a drop system). The skirting board looks damp. Some of the paint is bubbling and the beading along the bottom disintegrated when I put the hoover pipe against it. Eddie - I don`t think it`s the radiator joints because although they are green, the pipes that come out of the wall that connect to them are dry. Although both joints are green, the dampness seems to be down one end. It`s near a corner and the whole corner seems to be affected. I`m daunted by pulling the skirting board off or lifting up the block floor. I suppose my first port of call will have to be a plumber who can pull out the washing machine and have a good scout around on the other side. I`ve just had a recommendation for someone so I`ll start there, I guess. I really hope it isn`t something more serious. My sister has a large house and the wooden floors had to come up when she had a leak. The first thing she knew about it was when she lost her internet connection. It was a huge job. Scary.

[The Builder]

Hiya 237 .......... roughly how old is the house? Any idea of the construction?

[237SJ]

Hi The Builder. I was kinda hoping you`d turn up.
The house is a mid terrace 1975 (ish) house. I phoned a surveyor friend tonight (who is 200 miles away, unfortunately) and he said that there should be some sort of membrane underneath the floor that would stop any damp coming up from underneath if it turns out I have a drainage problem. He thinks it might be an internal plumbing problem. However, we both agreed that if it was a problem with the washing machine, there would be water seepage over the tiles in the kitchen (on the other side of the wall).

[237SJ]

By the way, it`s brick construction, solid floor.

[The Builder]

Yes, 1975.......... it'll have a floor membrane and proper dampcourse, so any problem there is highly unlikely. I had a similar problem in a pub recently. It turned out to be a leaking wastepipe from a basin in the adjoining WC.

First step would indeed be to look for something similar from the washing machine waste where it drains into the soil stack. A plumber or a general builder should be able to find it.

Do you have a Combi boiler. If so, then a drop in the water pressure in the boiler would indicate a rad leak. Check the pressure guage on the boiler.
Let us know how you get on.

[237SJ]

Yes I do have a combi and I have quite often had to let more water in the system due to the pressure dropping. The system is a drop system though so I can`t see why any radiator leak would affect the floor. I must admit, I have always wondered why I have to let more water into the system. I even think I asked a question about that on AB.

[237SJ]

By the way, my surveyor friend said something about the washing machine draining into the soil stack. I didn`t realise that it did but then I`m no expert. I really hope it just is something as simple as that.

[The Builder]

Perhaps your first choice would be to get a plumber rather than a builder. The amount of water circulating the rads is really quite small; only a few litres on a small system. Clean the copper fittings to the rad before the plumber gets there. Wire wool or a brillo pad, and give them a good scrape. Any leak would be far more noticeable then. :o)

[237SJ]

Hi again Buildier. A plumber came in tonight. Apparently, it`s a leak on a copper pipe where the water comes up into the house (stop-cock sort of area). It`s not major but has been leaking for quite a few months apparently and the water has seeped around. It`s simple to fix but getting to it is going to be difficult. Someone is going to have to take the sink out plus the kitchen unit and base board. This plumber was a great guy and came recommended by someone who does lettings so he`s got a whole network of pals that do different jobs and he`s given me the name of his mate who can do all the work. He wasn`t even going to charge me tonight so I bunged him £20 and everyone`s happy. Result! Thanks for all the replies.

[The Builder]

I'm glad you found it 237 :o)

It might be worth having your boiler serviced (pressure dropping). Nothing to do with the leak of course, but when it's serviced, he'll re-charge (pump up with a bicycle pump) the expansion vessel in the boiler .......... it's possibly why your losing pressure.

[237SJ]

Just got the work done tonight (as I`ve been away until now). It looks like the water followed the pipe down into the floor and travelled underneath the dividing wall and coming up in the living room. The plumber said the problem had been there for ages and he`s surprised my neighbours hadn`t noticed it on their side. I`ve got a dehumidifier that I was going to sell but I`m so glad I didn`t as I have a use for it now.